No clue, unless there were competing with other manufacturers.Any of you guys know why Sig designed the 15-round P365 mags with the flat back? I use that mag daily (when I walk through the door from work every day I drop the 10-round flush mag for the extended 15 for around the house). The 12-round mag is near-perfect, but that flat-back-15 always feels.....funny. I can't think of why they would not have made it like the 12-round mag with a shaped & textured back (palm-side).